Underglazing Pottery | Glazing Tips Tools and Ideas

a picture of a potter holding finished underglaze pottery

Using underglaze is a creative way to add designs and colors to your Pottery. The underglaze comes out through the actual glaze layer and forms beautiful patterns that give the pottery a professionally made look, adding character and depth to the surface.

There are plenty of techniques to apply underglazes, and you can make any design from simple strokes to intricate floral patterns.

If you’re a new Potter or don’t have much experience with Decorating Pottery, learning about the composition, types, and methods of using Underglazes can help you bring to life the imaginative and artistic designs in your head. 

To become a successful Potter and master the art of Underglazing, you must first learn what underglazes actually are, and what kinds of underglazes are available these days.

What is an Underglaze?

a picture of a finished underglazed jar

Underglazing is much like painting and drawing, giving you the ability to create gorgeous designs that cover pottery pieces. They’re commonly used under transparent glazes, but they can be used under light-colored, unsaturated and light-hue glazes.

But what exactly are Underglazes? Any decoration in a fluid form (mostly) that can be applied to a pottery surface before the glaze layer is called underglaze. This means that engobes, stains, slips, and all products marketed as underglazes fall into this category.

Basic Underglazes consist of Colorants, Clay, Water, and a small amount of frit. Frit is silica and flux (an oxide).

Popular Underglazes

Slips

In simple words, Slips are just, Thin Clay, Water, and Colorants – also known as Stains and Pigments. It has been a popular way to decorate pottery since ancient times. Technically Slip that can be applied to pottery at any stage, but the leather hard stage is the most popular and recommended. Due to the number of colors available in naturally occurring clay, slips can add distinctive, vibrant colors to the pottery they’re applied on.

a picture of green slip underglazed mug

There are a large number of techniques used to apply slips ranging from simply brushed strokes to paste-on-paste embellishments. Even complex abstract artworks are done on pottery using slips.

Underglaze Products

Underglaze has often been referred to as a fancy version of slip. The real difference is commercial underglazes contain frits that reduce shrinkage which allows them to be applied to greenware and bisque ware.

Disclaimer: We are ambassadors or affiliates for many of the brands we reference on the channel.  As an Amazon Associate, I earn from qualifying purchases. The tools used in this video, and in all of Pottery Crafters videos, are tools I use daily. The tools are also optional, being that you may have, and use many of them already.

Here are some Underglazes I use and recommend trying

Speedball Liquid Underglaze:

Speedball is the best, all-round liquid underglaze having great pigmentation. When it comes to having a choice of colors, this set of 2-ounce bottles has a beautiful array of twelve colors. I found these underglazes give you great coverage on Greenware and Bisque ware.

Sax True Flow Underglaze Set:

These are concentrated liquid colors that leave an opaque finish. They can be used to give both shiny effects and matte effects. You get nice coverage from True Flow Underglazes. Just one coat will cover depending on how thick you apply these underglazes, but 2 to 3 coats are recommended

Amaco Velvet Semi-Translucent Underglaze Set:

These Semi-Translucents are sprayable, and mixable colors give you a soft, velvety look to both Greenware and Bisque ware. Amaco Velvet underglaze has an excellent choice of colors that create beautiful designs, which makes the set of 12 perfect for mixing and matching. 

For more information on the Speedball, Sax True Flow, and the Amaco Velvet Semi-Translucent Underglaze sets listed above, Go to my Recommended Glazes Page.

How to Apply Underglaze

You should read the directions mentioned on the product’s label before applying an Underglaze. Nearly all commercially manufactured underglazes can serve their purpose on Wet Clay, Leather hard, Bone-dry Greenware, and Bisque ware.

a picture of underglazing pumpkin leaves
a picture of a holding a sponge underglazed mug

Using Underglaze also gives you more fluid to work with during designing, which acts as an advantage. If you want extra color detail, you could apply underglaze design on clay mold, bisque-fire it, and proceed to add more colors and design layers of underglaze before applying a final, transparent glaze coat. For more tips on glazing visit 27 Glazing Tips for you.

Underglazing the Greenware

Dry greenware is a sort of blank canvas when it comes to Underglazing. There are a number of benefits of applying underglaze to it.

a picture of a potter carving a tree
a picture of Mishima mug
a picture of wiping off underglaze
a picture of wax resisit decorated mug

Firstly, Underglazing on greenware lets you see what the finished design would look like. You could locate the parts that need more color, work or designing. Furthermore, pottery that is underglazed as greenware absorbs more vibrant colors.

To begin working on dry greenware (if it’s not abstract) you can use a pencil to mark or draw where you’ll apply the underglaze. Apply the underglaze by brushing, drawing or whichever method you prefer.

Try avoiding going over the underglaze and correcting it before it dries. Be very careful and don’t nudge your hand or smudge the art. Greenware clay quickly absorbs underglaze. Because of this, correcting any inconsistency may be harder.

When working on bone-dry greenware be very careful because it is at it’s most fragile state. 

Underglaze Your Bisque Ware

Just like Underglazing greenware has its perks, Underglazing bisque-ware also has its own. Bisque-fired pottery is firmer and much less fragile. Being firm also means it will withstand the pressure from pottery tools and you can Underglaze using Crayons, Pens, and Pencils without hurting the surface and making incisions and dents or chipping. The design tends to be more precise and cleaner.

To underglaze bisque ware, grasp the object with a clean, dry towel. You can make your design with a pencil first then apply your underglaze. The lead from the pencil will burn off in the kiln and will not leave any marks.

You might need to apply anywhere between 1to 3 coats depending upon the color saturation. After you’re done, apply a clear glaze topcoat and put the pottery in a Kiln.

Get Creative with Colors!

Commercial Underglazes are now manufactured in tons of different colors. They are composed of clay slips, many vibrant colorants, and frit.

There are a number of ways to apply them together and get wonderful designs. You can mix the colors together before applying them. Apply layers to get a brighter and more saturated tone. You can also layer contrasting colors. 

Underglazing is definitely a fun part of decorating your pottery. Keep in mind you may need to layer the colors as a single coat can be very soft and less pronounced. Here are just a few ways you can use your Underglaze:

Underglazing Ideas and Tools

Brushing

This technique is one of the most popular ways to apply underglaze. You can use any size you want to obtain the design you want to create, from a small detail brush to a large fan brush. Even if you can’t draw or paint you can create beautiful abstract designs. For more information see Different Brushes you can use for Glazing.

Sgraffito

Another popular technique where the potter carves through the glaze layers to reveal the clay body below. This form of abstract, high-contrast art that isn’t too hard to achieve. Just apply one or more underglaze layers to a wet or leather hard pottery piece and wait for the Underglaze to Dry and carve with Sgraffito and Detailing Tools carving tools. You can also use other caving tools to create your own unique design.

If you are applying more than one color, let the underglaze dry before you apply another coat. Don’t let your pottery become bone-dry because you will not be able to carve in it. The best time to start carving is when pottery is leather-dry.

Sponging

You can get pretty creative with a Sponge and some Underglaze. To get a few tips and ideas visit my Sponge Glazing article for more detailed information on this technique.

Transfers / Decals

Transfers and decals are another great way to decorate your clay.  

It’s easy to transfer underglaze drawings onto your pottery if you don’t want to or can’t draw them directly on to your piece. Apply your underglaze to Waxed Carbon Paper for Tracing (amazon).

Once the Underglaze is damp place the rice paper on your leather hard Pottery with the Underglaze facing down. Then rub the image gently with your damp sponge. Let the image dry and carefully peel off.  If you use too much water your image may blur.

You can also buy Ceramic Decals to add a new dimension to Underglazing.

Watercolor

Watercolor underglazes are another great to decorate your pottery giving your pottery that watercolor effect.

Watercolors can be used on leather hard, and dry greenware, but show the best results on bisque-fired pottery. Watercolor underglazes blend without a hassle and give more dimension to pottery pieces. The colors pop below the clear glaze and give amazing textures.

Bubble Underglazing

Bubble Underglazing is another fun way to decorate your pottery. You can read How To Bubble Glaze for more detailed information on this technique.

Mishima with wax

This technique with wax is my favorite. Brush underglaze on your leather hard pottery let dry and apply wax resist. After your Wax Resist is dry carve out a design with your ribbon tool or carving tool then apply another color of underglaze and wipe it off the waxed part the underglaze will stay in the inlayed area giving you a beautiful dimensional design. 

Pencil

These Pencils are great for drawing elaborate designs and give rich, vibrant colors that pop up from beneath the glaze layer.

For those of you who would much rather draw something, Amaco Underglaze Pencils are a great option. They show through glaze layers and allow space for detailing and defining. You can use underglaze pencils to write names and notes as well. Remember to only use underglaze pencils on bisque-fired pottery.

a picture of amaco underglaze pencils

👉 Amaco Underglaze Pencils
For the Current Price on Amaco Underglaze Pencils
at Amazon or Blick Arts


Conclusion

Underglazing is another fun way to decorate your pottery. The amount of different techniques you can choose from is great for potters in all different stages of skill levels. Which tool, technique and colors are you going use?

From the Benninger potters to the Experienced there is something for everyone when it comes to Underglazing. There is no limit to what you can create.

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